The protests come ahead of local elections in the country this weekend, which are a precursor to national elections in 2012.
They are the first serious protests experienced by Spain in several months, and mark a turn in the temper of the public, specifically the youth in Spain.
Youth unemployment is at 43%, and is even worse for those aged 16 to 19.
One protester, called Maria by Cotizalia, said, "What do my two courses give me, a masters and perfect English and French, if nobody has offered me my first job in my life?" (translation)